try looking at those occaisions as a chance to take notes. From the sounds of your post those are not all that frequent. When you walk into the dojo and see that someone who is prone to talk a lot is leading class, change your mindset for the session and instead of focusing on practicing so hard, focus on trying to take mental notes. Try out the little things that are being pointed out instead of trying to just practice (probably in the same way you always do) and use the session as a chance to expand your understanding a bit.
And if you get someone who's forcing you to a level of training you dont feel you are ready for, try just politely but bluntly telling them that there's a problem and what it is.
There's a good possibitly that they dont know they are doing that or that they are being rough.